from the world's big
Discovering Quorum Sensing
Bonnie Bassler is a professor of molecular biology at Princeton University. She has made important discoveries about quorum sensing, or the process by which single-cell bacteria communicate with one another. She hopes to use quorum sensing to create anti-microbial drugs to counteract bacteria. For her work, she received a MacArthur Fellowship in 2002 and the National Academy of Sciences elected her one of its members in 2006. She wakes up prior to 6 a.m. everyday to teach an aerobics class.. because otherwise she would just be lazy.
Question: What is quorum sensing?
Bonnie Bassler: We have been talking about things that are invisible,so bacteria are basically invisible to our eyes and yet we are covered with them, they are on us, they are in us, they are everywhere, and scientists have known about bacteria for almost 400 years, and what bacteria are are these primitive single-celled organisms, the way that they grow is they grow twice their size, their cut themselves down in the middle and then one becomes two. And so for all of these 400 years, everyone has thought that these bacteria are so primitive that they are just out there acting like these asocial organisms. But what we thought about and think about now is that there is no possibility that a bacteria could accomplish all the things they manage and most, like making us sick, lots of terrible things, but also lots of wonderful things, if they were just acting as these little individuals because they couldn’t have an influence on the environment. And so what we have shown and what quorum sensing is is the bacteria make and release tiny little molecules that you can think of like hormones, and so as the cells grow in numbers, these molecules grow on the outside of the cells. And when the molecules hit a certain amount, which is proportional to cell number, the bacteria detect that those molecules are there, so it is a way of counting neighbors, and then all the bacteria change their behavior in unison, and so they start carrying out tasks as enormous groups instead of trying to accomplish these tasks as individuals. So it is just like what we do, you know, if you need to move a piano from here to there, you don’t do it yourself, you wait, you get all your friends, and then you go one, two, three, and everybody does it together. So we call it quorum sensing, so they sort of vote with these chemical votes, they count the votes, and then they say we have enough to do it, and then they do it, whatever it is.
Recorded on: 6/17/08
Bonnie Bassler explains her breakthrough discovery.
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Health officials in China reported that a man was infected with bubonic plague, the infectious disease that caused the Black Death.
- The case was reported in the city of Bayannur, which has issued a level-three plague prevention warning.
- Modern antibiotics can effectively treat bubonic plague, which spreads mainly by fleas.
- Chinese health officials are also monitoring a newly discovered type of swine flu that has the potential to develop into a pandemic virus.
Bacteria under microscope
needpix.com<p>Today, bubonic plague can be treated effectively with antibiotics.</p><p style="margin-left: 20px;">"Unlike in the 14th century, we now have an understanding of how this disease is transmitted," Dr. Shanthi Kappagoda, an infectious disease physician at Stanford Health Care, told <a href="https://www.healthline.com/health-news/seriously-dont-worry-about-the-plague#Heres-how-the-plague-spreads" target="_blank">Healthline</a>. "We know how to prevent it — avoid handling sick or dead animals in areas where there is transmission. We are also able to treat patients who are infected with effective antibiotics, and can give antibiotics to people who may have been exposed to the bacteria [and] prevent them [from] getting sick."</p>
This plague patient is displaying a swollen, ruptured inguinal lymph node, or buboe.
Centers for Disease Control and Prevention<p>Still, hundreds of people develop bubonic plague every year. In the U.S., a handful of cases occur annually, particularly in New Mexico, Arizona and Colorado, <a href="https://www.cdc.gov/plague/faq/index.html" target="_blank">where habitats allow the bacteria to spread more easily among wild rodent populations</a>. But these cases are very rare, mainly because you need to be in close contact with rodents in order to get infected. And though plague can spread from human to human, this <a href="https://www.healthline.com/health-news/seriously-dont-worry-about-the-plague#Heres-how-the-plague-spreads" target="_blank">only occurs with pneumonic plague</a>, and transmission is also rare.</p>
A new swine flu in China<p>Last week, researchers in China also reported another public health concern: a new virus that has "all the essential hallmarks" of a pandemic virus.<br></p><p>In a paper published in the <a href="https://www.pnas.org/content/early/2020/06/23/1921186117" target="_blank">Proceedings of the National Academy of Sciences</a>, researchers say the virus was discovered in pigs in China, and it descended from the H1N1 virus, commonly called "swine flu." That virus was able to transmit from human to human, and it killed an estimated 151,700 to 575,400 people worldwide from 2009 to 2010, according to the Centers for Disease Control and Prevention.</p>There's no evidence showing that the new virus can spread from person to person. But the researchers did find that 10 percent of swine workers had been infected by the virus, called G4 reassortant EA H1N1. This level of infectivity raises concerns, because it "greatly enhances the opportunity for virus adaptation in humans and raises concerns for the possible generation of pandemic viruses," the researchers wrote.
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- The terms 'education' and 'learning' are often used interchangeably, but there is a cultural connotation to the former that can be limiting. Education naturally links to schooling, which is only one form of learning.
- Gregg Behr, founder and co-chair of Remake Learning, believes that this small word shift opens up the possibilities in terms of how and where learning can happen. It also becomes a more inclusive practice, welcoming in a larger, more diverse group of thinkers.
- Post-COVID, the way we think about what learning looks like will inevitably change, so it's crucial to adjust and begin building the necessary support systems today.
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- Selfish behavior has been analyzed by philosophers and psychologists for centuries.
- New research shows people may be wired for altruistic behavior and get more benefits from it.
- Times of crisis tend to increase self-centered acts.